After continuous casting, continuously cast workpieces, slabs in particular, are generally given a surface treatment in order to achieve a sufficient level of quality during the subsequent processing of the workpiece. When the continuously cast slabs are ground, the slab is typically moved with a reciprocating motion back and forth longitudinally under a grinding apparatus (grinder). At the end of each stroke, the grinding apparatus is stepped transversely until the entire surface of the slab has been ground. The slab is supported on a grinding table resting lengthwise on its broad face.
EP 0 053 274 describes a generic apparatus as known in the prior art for grinding slabs.
In so-called HP grinding (high-pressure grinding) of the slab, a sufficient grinding removal rate must be achieved for reasons of economic efficiency. The material-removal rate can be increased here by increasing the width of the grinding wheel if the driving output of the motor is increased simultaneously (for example from 315 kW to 630 kW while doubling the width of the grinding wheel); this approach thus allows the specific motor output to be maintained as the same level relative to the width of the grinding wheel. However, the grinding wheel is limited by the strength of the binder of the grinding wheel; it is not possible in practice to use grinding wheels greater than 150 mm in width.
A known approach is therefore to employ, in particular, two grinding wheels side-by-side on a grinding spindle. The disadvantage of this approach, however, is the fact that the contact zone between grinding wheel and workpiece to be ground io wanders across the width of the grinding wheel, and in fact the contact zone wanders periodically back and forth from each outer edge of the grinding wheel to the center of the grinding wheel due to the reversing of the slab. Widening the contact zone and increasing the drive output thus do not necessarily produce the desired increase in the material removal rate, but may result merely in increasing the service life of the grinding wheel(s).
As a result, it cannot be assumed that using double grinding wheels on a drive spindle will also yield a doubling of the material removal rate.